Rock drill



Aug. 6, 1940.

A. FEUCHT 2.210532 ROCK DRILL Filed 001;. 13, 1959 2 Sheets-Sheet l M wM 27 78 I LA I II lNVENTOR ALBERT PEI/CH7 BY n ATTORNEY Aug. 6, 1940.

A. FEUCHT 2.210.532

ROCK DRILL 2 Sheets-Sheet 2 Filed Oct. 15, 1-939 lNVENTOR ALBERT FEUCHTW v ATTORNEY Patented Aug. 6, 1940 UNITED STATES PATENT OFFICE ROCKDRILL Application October 13,

8 Claims.

This invention relates broadly to percussive machines, but moreparticularly to fluid actuated drilling apparatus of the stoper type.

One object of this invention is to improve the present mechanism forfeeding and holding the drill to the work.

Another object of this invention. is to provide the fluid actuatedfeeding mechanism of a stoper with 'an improved recoil checkingmechanism preventing recoil movement of the drilling motor relative tothe work during normal drilling operations.

Another object of this invention is to provide the fluid actuatedfeeding mechanism of a rock drill with a device calculated to maintainthe drilling tool to the work irrespective of variations in the pressureof the motive fluid actuating the feeding mechanism.

Another object of this invention is the provision in a fluid actuatedfeeding mechanism for a rock drilling motor of a recoil checkingmechanism which may be released by the simple manipulation of the mainthrottle normally controlling the admission of motive fluid to the drillmotor.

Other objects and advantages more or less ancillary to the foregoingreside in the specific construction and aggroupment' of the elementspeculiar to this structure, as'will become apparent from a more completeexamination of this specification.

' In the drawings:

Fig. 1 is a side elevational view of a stoper embodying the invention.

35 Fig. 2 is a longitudinal view of the improved feeding mechanismincorporated in the stoper shown in Fig. 1.

Fig. 3 is a cross sectional view taken indicated by line 3-3 in Fig. 2.

4 Figs. 4, 5, 6 and '7 are cross sectional views taken in a planeindicated by line 4-4 in Fig. 2,

illustrating the throttle valve in different positions.

Figs. 8,9, 10 and 11 are cross sectional views of the throttle valvetaken in a plane indicated ,by line 88 in Fig. 2, illustrating thethrottle valve in the same positions as shown in Figs. 4, 5, 6 and '7respectively.

Figs. 12, 13, 14 and 15 are alsocross sectional 0 views of the throttlevalve taken in a plane indicated by line |2|2 in Fig. 2 illustrating thethrottle valve in the same positions as shown in Figs. 4, 5, 6 and 7respectively.

, Fig. 16 is an enlarged portion in section of the recoil checkingmechanism shown in Fig. 2.

in a plane 1939, Serial No. 299,233

Fig. 17 is a view similar to Fig. 16 illustrating the recoil checkingmechanism in inoperative position.

Fig. 18 is a cross sectional view taken in a plane indicated by linel8--l8 in Fig. 2. 6

Fig. 19 is a longitudinal sectional view taken in a plane indicated byline Ill-l9 in Fig. 2.

Fig. 20 is a longitudinal sectional view of the central portion of thedrilling motor taken in a plane indicated by line 20-20 in Fig. 1.

Fig. 21 is a longitudinal sectional view of the handle also shown inFig. 1.

Fig. 22 is a view similar to Fig. 20 illustrating a. modification of theinvention.

Referring to the drawings, 25 represents the 15 cylinder of the drillingmotor within which is reciprocably mounted a piston (not shown) capableof delivering impacts on a drill steel 26 slidably mounted within achuck 21, which is rotatably mounted within a front housing 28. Mountedcoaxially with the cylinder 25, there is a head 29 against which reststhe flange 30 of a feed cylinder or housing 3! depending from thecylinder 25 in coaxial relation therewith. The front housing 28, head 29and flange 30 are 5 rigidly secured to the cylinder 25 by two side bolts32.

Slidably mounted within the feed cylinder 3|, there is a piston cylinder33 closed at its lower end We plug 34 carrying a removable groundengaging pointed end 35. On the inner end, the piston cylinder 33carries a piston 36 equipped with packing rings 31 in fluid tightslidable engagement with the inner wall of the feed housing 3|. Thispiston rests on an annular shoulder .35 33 formed on the cylinder 3| andis held in position by a retaining nut 39. The cylinder 33 is formedwith a buttless internal screw thread 40 having a straight face 4i andan outwardly inclined face 42, the thread being of an angle of about twoto three degrees, thereby actually producing the equivalent of annularratchet teeth formed .on the inner wall of the piston cylin-' der 33. i

Depending from the head 29 into the piston cylinder 33, there is, aninner tube 43 slidably mounted within the piston cylinder 33. This innertube is closed at its lower end by a plug 44 formed with an arcuatedseat 45 extending laterally therethrough and within which is swingablymounted the trunnion 46 of a pawl 41 depending therefrom and having asemicircular wedgeshaped operating edge 48 engageable with the flat face4! of the teeth or threads 4, as clearly shown in Fig. 16. At a placediametrically opposed to the operating edge of the pawl 41, the plug Mis provided with adepending lug 49 against which rests a spring pressedplunger 5!] radially carried by the pawl 41 for constantly urging thepawl in engagement with the thread Intermediate its ends, the trunnion46 of the pawl all is provided with a slot 5| formed with an inclinedbottom wall 52 leading toward the operating edge 68 of the pawl.

Within the flange 30, there is provided chamber closed at its upper endby the head '5 of a gland 55 screwed within the adjacent portion of thehead 29, which gland holds in position a water tube 56 through whichcleansing fluid is admitted to the free end of the drill steel Slidablymounted within the chamber 53, there is the cylindrical head 51 of a rod58, which extends into the inner tube 43 for end engagement with thebottom wall 52 of the slot El provided in the pawl 41. Interposedbetween the head of the rod 58 and the gland 55, there is a compressionspring 59 constantly urgingthe rod 53 downwardly, while the chamber 53above the head is constantly vented to the atmosphere no AQU- through aport 75.

Formed on the head 29, there is a laterally projecting boss [it withinwhich is rotatably mounted a throttle valve 6i having a shank 62extending through one end of the boss to receive an operating handle 53.Swivelly mounted within the other end of the boss 62, there is a motivefluid connection fi l through which motive fluid may be admitted into acentral bore 65 provided in the throttle valve 6 I. Toward its shankedend, the peripheral wall of the throttle valve 6| is provided with asemicircular groove 66 capable of communication with a vent 61 leadingfrom the. valve to the atmosphere and with a port 58 leading in thebottom of the chamber 53 within which is slidably mounted the head 57 ofthe rod 58. Within the same vertical plane of the, annular groove 36,the throttle valve is also pro-, vided with a radial port 69.

Longitudinally spaced from the groove 66, the valve BI is also providedwith an enlarged radial, port ll) of V-shaped cross section capable ofcommunication with a passage leading into the, cylinder 25, and in thesame vertical plane with a semicircular groove "H From this groove leadsa longitudinally extending groove l2 ending within a vertical planeadjacent the inner end of, the throttle valve and capable ofcommunication with a port '52 leading in the upper end of the feedhousing 3|. Within the last named vertical plane, the throttle valve isalso provided with a semicircular groove 73 in constant communicationwith the valve bore 6! through a port it.

In Fig. there is shown the usual feed release port 76 leading from theupper end of the feed cylinder 3! to the shank T! of a handle l8extending laterally from the cylinder in the usual manner. This port 56is normally controlled by. a spring seated valve 19 movable into openposi-. tion by a slidable rod 80 operable through a hand operated cam81. When the valve l9 opens, as shown in Fig. 21, motive fluid from thefeed cylinder may exhaust to the atmosphere through an exhaust port 82.

In Fig. 22, there is shown a modification of the invention including aport 83 connecting the bottom of the chamber 53 with the upper end ofthe feed cylinder 3|, the purpose of which will be explained later.

In the operation of the device, with the throttle valve as shown inFigs. 4, 8 and 12, the motive fluid admitted into the bore 65 of thethrottle valve through the connection 64 is prevented from flowing intothe machine and the feeding mechanism, thereby preventing operation ofthe drilling apparatus. As the throttle is rotated from, the positionshown in Fig. 12 to that in Fig. 13, motive fluid from the throttlevalve bore 65 ad-. mitted into the valve groove 13 through the port, It,will flow into the upper end of the feed cylinder 3i through the port72, thereby acting on. the piston 36 causing feeding motion of thedrilling motor toward the Work. In this instance, it will be noticedthat the inlet port 10 is stilt spaced from the port it, therebyenabling feed ing of the drill without admitting motive fluid into thedrilling motor 25. In this last position of the valve, its inlet port 69in Fig. 5, is still spaced from the supply port 63 to the bottom ot thechamber 53, thereby causing the rod 58 to assume a downward extremeposition relative to, the inner tube 43 and consequently exerting pres-.sure on the inclined bottom wall 52 of the pawls slot as for maintainingthe pawl 47 out of engagement with the threads 40. I

As the throttle valve is rotated from the posi tion shown in Fig. 13 tothat in Fig. 14, motive fluid is still supplied to the feed cylinder 3|through the valve groove 13 and supply port 12, In this new position ofthe throttle valve, the

narrow portion of the V-shaped inlet passage 10,

is in communication with the port if! for admit-. ting a limited amountof motive fluid to the cyla inder 25 for eifecting reciprocation of thehammer in a manner calculated to deliver light im-,

pacts to the drill steel 23, a condition which has been found desirablewhen starting the drill hole, In this position of the throttle valve, itwill be seen that the valve port 69 is still in spaced rela-. tion withthe supply port 68, thereby enabling the rod 58 to remain in operativeengagement with the pawl 4 for holding it in inoperative position.

After the throttle valve has been rotated into full operative positionas shown in Figs. 7, 11.

and 15, the supply of the motive fluid to the feed cylinder still takesplace through the valvegroove l3 and port 12. In this instance, thevalve supply passage IB is in full communication with the passage '10,while the valve port 69 is now in, communication with the supply port:68, thereby admitting motive fluid to the bottom of the chamber 53 toact under the head 5'! of the rod 58 for, moving the rod and head intothe position shown in Fig. 2 against the effect of the compression,spring 59, consequently enabling the spring, pressed plunger to move thepawl 4'! into opera ative engagement with the ratchet teeth 4B. As thedrilling operation proceeds, the drilling motor 25 together with theinner tube 43 and conse-r quently with the pawl 4i will move upwardlyrela tive to the piston tube 33. In this instance, the,

pawl 38 pressed by the spring pressed plunger will simply ride theratchet teeth ll] andsuccessively engage the flat faces 4! thereof topre-' vent recoil movement of the drilling motor relative to the feedpiston 33, thereby maintaining the drill steel 26 in engagement with theWork and preventing up and down motion of the drilling motor.

When it is desired to release or disengage the recoil checkingmechanism, the operator may move the throttle valve 6! into any of thepositions shown in Figs. 4 to 6, in which instance the supply port 68leading from the bottom of the chamber 53 is put in communication withthe atmosphere through the vent or exhaust port'tl,

thereby relieving the pressure under the head 51 of the rod 58 andenabling the compression spring 59 to drive the rod downwardly forcausing the disengagement of the pawl 41 with the ratchet teeth in asclearly shown in Fig. 17.

In the modification shown in Fig. 22, the ports and passages shown inFigs. 4 to 7 inclusive may be omitted. this instance, the bottom of thechamber a. is in direct communication with the upper end of the feedcylinder 3i through the port 83, thereby causing the rod 58 to assumethe'position shown in Fig. 16 as soon as motive fluid is admitted intothe air feed cylinder, that is, in any position of the throttle valveshown in Figs. 13 to 15, and consequently enabling the operativeengagement .of the pawl ll with the ratchet teeth 46. In this instance,the disengagement of the pawl will take place when the motive fluidpressure is released from the feed cylinder 3! by the operator actuatingthe cam 85 for opening the valve it, thereby enabling free exhaust ofthe motive fluid via the port it, the now opened valve is and theexhaust port 82, and resulting in a drop of pressure in the chamber 53permitting the spring ES to drive the rod 58 downwardly to causethe-disengagement of the pawl M.

Although the foregoing description is necessarily of a detailedcharacter, in order to completeiy set forth the invention, it is to beunderstood that the specific terminology is not intended to berestrictive or confining and it is to be further understood that variousrearrangements of parts and modifications of structural detail may beresorted to without departing from the scope or spirit of the inventionas herein claimed.

I claim:

1. In a drilling apparatus, the combination with a drilling motor, of afeeding mechanism for said motor including feed housing fixed to themotor, a fluid actuated piston cylinder tele-v scopically mounted insaid housing, of an inner tube in said cylinder fixed to said motor,longitudinally spaced teeth on the inner wall of said cylinder, a pawlpivotally carried by the inner end of said tube for operative engagementwith said teeth to prevent recoil movement of the motor relative to saidcylinder, and a rod slidable in said tube engageable with said pawl foreffecting its disengagement from said teeth to permit the collapse ofsaid feeding mechanism.

2. In a drilling apparatus, the combination with a drilling motor, of afeeding mechanism for said motor including a feed housing fixed to themotor, a fluid actuated piston cylinder telescopically mounted in saidhousing, of an inner tube in said cylinder fixed to said motor,longitudinally spaced teeth on the inner wall of said cylinder, a pawlpivotally carried by the inner end of said tube for operative engagementwith said teeth to prevent recoil movement of the motor relative to saidcylinder, and means in said tube operatively engageable with said pawlfor eflecting its disengagement from said teeth to permt the collapse ofsaid feeding mechanism.

3.111 a drilling apparatus, the combination with a drilling motor, of afeeding mechanism for said motor including a feed housing fixed to themotor, a fluid actuated piston cylinder telescopically mounted in saidhousing, a throttle valve for controlling admission .of the motive fluidto said piston cylinder, of an inner tube in said cylinder fixed to saidmotor, longitudinally spaced teeth on the inner wall of said cylinder, apawl pivotally carried by the inner end of said tube for operativeengagement with said teeth to prevent recoil movement of the motorrelative to said cylinder, a rod slidable in. said tube engageable withsaid pawl for effecting its disengagement from said teeth to permit thecollapse of said feeding mechanism, and means including said throttlevalve for controlling the slidable movement of said rod.

4. In a drilling apparatus, the combination with'a drilling motor, of afeeding mechanism for said motor including a, feed housing fixed to themotor, a fluid actuated piston-cylinder telescopically mounted in saidhousing, of a recoil checking mechanism comprising a tube in saidcylinder fixed to said motor, longitudinally spaced teeth on the innerwall of said cylinder, a pawl carried by said tube operatively engag ingsaid teeth, and means effecting disengagement of said pawl from saidteeth.

5. In a drilling apparatus, the combination with a drilling motor, of afluid actuated feeding and supporting mechanism for said motor includinga feed housing fixed to the motor having a piston-cylindertelescopically mounted therein, a throttle valve for controllingadmission of motive fluid to said mechanism, of a recoil checking devicebetween said motor and cylinder, a slidable rod in said housingoperatively associated with said device for rendering it inoperative,and means including said throttle valve for controlling slidablemovement of said rod.

6. In a support for a drilling motor, a pair of telescopically mountedelements, means including a throttle valve for admitting motive fluid inthe outer element for effecting the extension stroke of said elements, areleasable lock between said elements normally preventing thecompression stroke thereof, and means controlled by said throttle valvefor effecting the release of said lock.

'7. In a support for a drilling motor, a pair of telescopically mountedelements, means including a throttle valve for admitting motive fluid tosaid elements for effecting the extension stroke thereof, a releasablelock between said elements normally preventing the compression strokethereof, a slidable rod operatively engageable with said lock forefiecting its release, and means including said throttle valve forcontrolling the slidable movement of said rod.

8. In a support for a drilling motor, a pair of ALBERT FEUCHT.

